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Network Design
Network planning and design is an iterative process, encompassing topological design, network-synthesis, and network-realization, and is aimed at ensuring that a new telecommunications network or service meets the needs of the subscriber and operator.Penttinen A., ''Chapter 10 – Network Planning and Dimensioning, Lecture Notes: S-38.145 - Introduction to Teletraffic Theory'', Helsinki University of Technology, Fall 1999. The process can be tailored according to each new network or service.Farr R.E., ''Telecommunications Traffic, Tariffs and Costs – An Introduction For Managers'', Peter Peregrinus Ltd, 1988. A network planning methodology A traditional network planning methodology in the context of business decisions involves five layers of planning, namely: * need assessment and resource assessment * short-term network planning * IT resource * long-term and medium-term network planning * operations and maintenance. Each of these layers incorporates plans for different t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Network Planning Methodology
A, or a, is the first Letter (alphabet), letter and the first vowel of the Latin alphabet, Latin alphabet, used in the English alphabet, modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is English alphabet#Letter names, ''a'' (pronounced ), plural English alphabet#Letter names, ''aes''. It is similar in shape to the Greek alphabet#History, Ancient Greek letter alpha, from which it derives. The Letter case, uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English grammar, "English articles, a", and its variant "English articles#Indefinite article, an", are Article (grammar)#Indefinite article, indefinite arti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Congestion
Network congestion in data networking and queueing theory is the reduced quality of service that occurs when a network node or link is carrying more data than it can handle. Typical effects include queueing delay, packet loss or the blocking of new connections. A consequence of congestion is that an incremental increase in offered load leads either only to a small increase or even a decrease in network throughput. Network protocols that use aggressive retransmissions to compensate for packet loss due to congestion can increase congestion, even after the initial load has been reduced to a level that would not normally have induced network congestion. Such networks exhibit two stable states under the same level of load. The stable state with low throughput is known as congestive collapse. Networks use congestion control and congestion avoidance techniques to try to avoid collapse. These include: exponential backoff in protocols such as CSMA/CA in 802.11 and the similar CSMA/CD i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Partition
A network partition is a division of a computer network into relatively independent subnets, either by design, to optimize them separately, or due to the failure of network devices. Distributed software must be designed to be partition-tolerant, that is, even after the network is partitioned, it still works correctly. For example, in a network with multiple subnets where nodes A and B are located in one subnet and nodes C and D are in another, a partition occurs if the network switch device between the two subnets fails. In that case nodes A and B can no longer communicate with nodes C and D, but all nodes A-D work the same as before. As a CAP trade-off The CAP Theorem is based on three trade-offs: consistency, availability, and partition tolerance. Partition tolerance, in this context, means the ability of a data processing system to continue processing data even if a network partition causes communication errors between subsystems. External links Partition of the Large Netw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing Protocol
A routing protocol specifies how routers communicate with each other to distribute information that enables them to select routes between nodes on a computer network. Routers perform the traffic directing functions on the Internet; data packets are forwarded through the networks of the internet from router to router until they reach their destination computer. Routing algorithms determine the specific choice of route. Each router has a prior knowledge only of networks attached to it directly. A routing protocol shares this information first among immediate neighbors, and then throughout the network. This way, routers gain knowledge of the topology of the network. The ability of routing protocols to dynamically adjust to changing conditions such as disabled connections and components and route data around obstructions is what gives the Internet its fault tolerance and high availability. The specific characteristics of routing protocols include the manner in which they avoid rou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Switch
A network switch (also called switching hub, bridging hub, and, by the IEEE, MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device. A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer (layer 2) of the OSI model. Some switches can also forward data at the network layer (layer 3) by additionally incorporating routing functionality. Such switches are commonly known as layer-3 switches or multilayer switches. Switches for Ethernet are the most common form of network switch. The first MAC Bridge was invented in 1983 by Mark Kempf, an engineer in the Networking Advanced Development group of Digital Equipment Corporation. The first 2 port Bridge product (LANBridge 100) was introduced by that company shortly after. The company subsequently produced multi-port switches for both Ethernet and FDDI such as GigaSwitch. Digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrix (mathematics)
In mathematics, a matrix (plural matrices) is a rectangular array or table of numbers, symbols, or expressions, arranged in rows and columns, which is used to represent a mathematical object or a property of such an object. For example, \begin1 & 9 & -13 \\20 & 5 & -6 \end is a matrix with two rows and three columns. This is often referred to as a "two by three matrix", a "-matrix", or a matrix of dimension . Without further specifications, matrices represent linear maps, and allow explicit computations in linear algebra. Therefore, the study of matrices is a large part of linear algebra, and most properties and operations of abstract linear algebra can be expressed in terms of matrices. For example, matrix multiplication represents composition of linear maps. Not all matrices are related to linear algebra. This is, in particular, the case in graph theory, of incidence matrices, and adjacency matrices. ''This article focuses on matrices related to linear algebra, and, unle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teletraffic Grade Of Service
In telecommunication engineering, and in particular teletraffic engineering, the quality of voice service is specified by two measures: the grade of service (GoS) and the quality of service (QoS). Grade of service is the probability of a call in a circuit ''group'' being blocked or delayed for more than a specified interval, expressed as a vulgar fraction or decimal fraction. This is always with reference to the busy hour when the traffic intensity is the greatest. Grade of service may be viewed independently from the perspective of incoming versus outgoing calls, and is not necessarily equal in each direction or between different source-destination pairs. "Grade of Service" sometimes means a measure of inbound call center traffic to verify adherence to conditions to measure the success of customers served. On the other hand, the quality of service which a ''single'' circuit is designed or conditioned to provide, e.g. voice grade or program grade is called the quality of service. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overprovisioning in a solid-state drive
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Overprovisioning can refer to: *Allocating additional bandwidth in *Allocation of additional storage space required to mitigate write amplification Write amplification (WA) is an undesirable phenomenon associated with flash memory and solid-state drives (SSDs) where the actual amount of information physically written to the storage media is a multiple of the logical amount intended to be wr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications Forecasting
All telecommunications service providers perform forecasting calculations to assist them in planning their networks.Farr R.E., Telecommunications Traffic, Tariffs and Costs – An Introduction For Managers, Peter Peregrinus, 1988. Accurate forecasting helps operators to make key investment decisions relating to product development and introduction, advertising, pricing etc., well in advance of product launch, which helps to ensure that the company will make a profit on a new venture and that capital is invested wisely.Kennedy I. G., Forecasting, School of Electrical and Information Engineering, University of the Witwatersrand, 2003. Why is forecasting used? Forecasting can be conducted for many purposes, so it is important that the reason for performing the calculation is clearly defined and understood. Some common reasons for forecasting include: *Planning and Budgeting – Using forecast data can help network planners decide how much equipment to purchase and where to place it t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Measurement (telecommunications)
Measurement of traffic within a network allows network managers and analysts to both make day-to-day decisions about operations and to plan for long-term developments.Penttinen A., ''Chapter 4 – Traffic Modelling and Measurements'', Lecture Notes: S-38.145 - Introduction to Teletraffic Theory, Helsinki University of Technology, Fall 1999.Kennedy I., ''Why Traffic Measurement? School of Electrical and Information Engineering, University of the Witwatersrand, 2003 Traffic Measurements are used in many fundamental activities such as: *Identification of traffic patterns and trends *Calculating the traffic intensity in a specific circuit or group *Monitoring the service *Dimensioning and managing the network *Calculating tariffs *Performing forecasting *Dimensioning and managing the SS7 network *Checking the performance of the common channel signalling network The following sections will answer some fundamental questions about Traffic Measurement, such as: What should be measured; w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Intensity
In telecommunication networks, traffic intensity is a measure of the average occupancy of a server or resource during a specified period of time, normally a busy hour. It is measured in traffic units ( erlangs) and defined as the ratio of the time during which a facility is cumulatively occupied to the time this facility is available for occupancy. In a digital network, the traffic intensity is: : \frac where :''a'' is the average arrival rate of packets (e.g. in packets per second) :''L'' is the average packet length (e.g. in bits), and :''R'' is the transmission rate (e.g. bits per second) A traffic intensity greater than one erlang means that the rate at which bits arrive exceeds the rate bits can be transmitted and queuing delay will grow without bound (if the traffic intensity stays the same). If the traffic intensity is less than one erlang, then the router can handle more average traffic. Telecommunication operators are vitally interested in traffic intensity, as it dic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications Network
A telecommunications network is a group of nodes interconnected by telecommunications links that are used to exchange messages between the nodes. The links may use a variety of technologies based on the methodologies of circuit switching, message switching, or packet switching, to pass messages and signals. Multiple nodes may cooperate to pass the message from an originating node to the destination node, via multiple network hops. For this routing function, each node in the network is assigned a network address for identification and locating it on the network. The collection of addresses in the network is called the address space of the network. Examples of telecommunications networks include computer networks, the Internet, the public switched telephone network (PSTN), the global Telex network, the aeronautical ACARS network, and the wireless radio networks of cell phone telecommunication providers. Network structure In general, every telecommunications network conceptually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
